Enzyme-Linked Immunospot Assay Responses to Early Secretory Antigenic Target 6, Culture Filtrate Protein 10, and Purified Protein Derivative among Children with Tuberculosis: Implications for Diagnosis and Monitoring of Therapy

• Published in: Clinical infectious diseases Vol. 40; no. 9; pp. 1301 - 1308
• Main Authors: Nicol, M. P., Pienaar, D., Wood, K., Eley, B., Wilkinson, R. J., Henderson, H., Smith, L., Beatty, D.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.05.2005; University of Chicago Press; Oxford University Press
• Subjects: Antigens; Antigens, Bacterial - immunology; Antitubercular Agents - therapeutic use; Bacterial diseases; Bacterial Proteins - immunology; Biological and medical sciences; Child; Child, Preschool; Childhood; Children; Children & youth; Cutaneous tuberculosis; Diagnostic tests; Drug Administration Schedule; Enzyme-Linked Immunosorbent Assay; Human bacterial diseases; Humans; Immunoassay; Infections; Infectious diseases; Major Articles; Medical sciences; Mycobacterium tuberculosis; Sensitivity and Specificity; T lymphocytes; Tuberculin; Tuberculin - immunology; Tuberculosis; Tuberculosis - diagnosis; Tuberculosis - drug therapy; Tuberculosis and atypical mycobacterial infections; Tuberculosis vaccine; Human; Infection; Tuberculin PPD; Treatment; Tuberculosis; Surveillance; Bacteriosis; Early; Mycobacterial infection; Diagnosis; Child; Protein
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1086/429245

Background. The ability to detect tuberculosis-specific lymphocytes by enzyme-linked immunospot (ELISPOT) assay may have important implications for the diagnosis and monitoring of tuberculosis in children, for which routine methods lack sensitivity. We conducted a study to determine the presence and time course of ELISPOT responses in children with tuberculosis. Methods. Blood samples were obtained from children with a clinical diagnosis of tuberculosis, and interferon-γ ELISPOT assays were performed using purified protein derivative (PPD), early secretory antigenic target 6 (ESAT-6), and culture filtrate protein 10 (CFP10) as stimulants. A subset of children were retested after 1, 3, and 6 months of therapy. Results. Detectable responses to ESAT-6 or CFP10 were found in 49 of 70 children with clinical tuberculosis but were more frequently found in those with culture-proven disease (P = .05). The number of subjects with responses to PPD increased after 1 month of therapy (P = .0004) and decreased at 3 and 6 months. Conclusion. Tuberculosis-specific ELISPOT testing is a promising tool that should be evaluated as a potential diagnostic test for childhood tuberculosis. We caution against the use of an early decrease in response as a marker of successful antituberculous chemotherapy.